Malaysian Jet Will Be Found Along '7th Arc': Australian Bureau

New data suggest that the missing Malaysia Airlines jet will be found along “the 7th arc” in the Indian Ocean, the Australian Transport Safety Bureau said Thursday.

The bureau said on its website that “new information and analysis” shows that Flight 370 would have exhausted its fuel by the time it reached “the 7th arc.” That’s the point where the jet’s last hourly transmission, or “handshake,” with a satellite occurred. At that point, the bureau said, the aircraft must have been descending.

“As a result, the aircraft is unlikely to be more than 20 NM (38 km) to the west or 30 NM (55 km) to the east of the arc,” the bureau said.

The "7th arc" is shown on a map released by the Australian Transport Safety Bureau.Australian Transport Safety Bureau

It said the arc reaches from 20 degrees south latitude to 39 degrees south latitude. It said that refinements in the analysis would produce a target search area of about 17,500 square nautical miles, with a length along the arc of about 350 nautical miles.

Last week, the bureau ruled out a previous target area of 300 square miles where sonic “pings” thought to possibly be coming from the jet’s black boxes were heard in April. That search was 1,000 miles off the northwest coast of Australia.

The new area is far, far larger. The bureau’s chief commissioner, Martin Dolan, said in an interview with The Associated Press that searchers were “cautiously optimistic” that the plane could be found.

Flight 370 disappeared March 8 on a flight from Kuala Lumpur, Malaysia, to Beijing with 239 people aboard. No trace has been found.

But an analysis released Wednesday by scientists in Australia said an indistinct rumbling on a five-second audio clip could be a new lead -- the moment the jet hit the water.